During Mayor Bowser’s Vision Zero Week last month, she announced a plan to make it illegal to take a right turn on red (RTOR) in about 100 of intersections within DC’s downtown core. 2016 legislation required the change; it was not exclusively a result of newfound Vision Zero energy. Research is mixed that there are positive safety impacts to restricting RTORs. Creating default rules with few, clearly noted, exceptions is superior to policies that change frequently and confuse drivers.
DDOT to Eliminate Right Turns on Red in 100 DC Intersections
WTOP first reported that DC was considering a near-universal ban on right turns during red lights, but DDOT said the next day they’re planning to snuff the move out in 100 intersections within DC’s central business district. Mayor Bowser announced the policy at an October 23rd breakfast, along with several other measures designed to increase road safety for all users. The changes are supposed to happen early 2019.
DC’s Red Light Right Turn Move Was Required, Not a Reaction to Poor Vision Zero Results
Many of Mayor Bowser’s administration discussed the RTOR restriction in the context of the city’s Vision Zero effort that has failed to reduce traffic deaths in DC. Those deaths and injuries have gone up since DC’s effort started in 2015. With her “Vision Zero Week,” Bowser’s message was redoubled effort given the poor results. However, Greg Billing of the Washington Area Bicyclist Association notes that this RTOR restriction was already mandated by 2016 legislation.
“Eliminating Right Turns on Red is actually mandated by DC Council legislation in the Bicycle and Pedestrian Safety Amendment Act of 2016. The law requires the Mayor via DDOT to establish Bike/Ped Priority Areas that would be where additional safety strategies should be implemented such as eliminating RTOR, lower speed limits (20 mph), protected bike lanes, and additional automated enforcement.”
RTOR restrictions and many of the Mayor’s other Vision Zero Week announcements—like longer times for pedestrians to cross the street—were already required and not a change or course or an increased vigilance against increases in DC street danger.
Right Turns On Red Aren’t Necessarily Dangerous or Green
The Washington Post put together a great collection of research on RTOR safety. The upshot is that restricting RTORs doesn’t necessarily improve safety. The federal government allowed the rouge rights first in the 1970s to save on gas and commuters’ time during the oil crisis. A few early studies showed increased crashes and deaths, but the inquiries had several methodological limits: low sample sizes, not much data on each collision, and—the kicker—ignored whether the light at that intersection was red or green when the driver made the turn. They separated intersections and compared danger by which intersections allowed RTORs. Not knowing the light status means you didn’t know if all right turns were a problem.
Since the 1970s and 80s, data from traffic accidents have gotten more plentiful and research has gotten more precise about the factors that affect collisions and danger. Traffic Engineers studying San Francisco in 2012 “found that only 0.45 percent of crashes involved someone making a right turn on red. The report also noted that these findings were in line with a 1956 study of San Francisco intersections, which found 0.3 percent of collisions occurred when someone was making a right on red. Both the 2002 and the 1956 study concluded that, if anything, making a right turn on red was no more dangerous than making a right turn on green.”
The way the Post describes red light danger isn’t ideal. What you want to know is how much more dangerous RTORs make an intersection, not what portion of total crashes occurs with RTORs. You want to know if RTORs make a collision more likely at an intersection versus a comparable one with no RTOR. You want to know that allowing RTOR makes a crash more dangerous to the participants than an accident at a similar intersection with no RTOR. The increased likelihood of a collision, and the effect, if any, on a crash’s danger, are the key factors.
The stated reason for allowing RTORs in the 70s was to save on gas used by the cars at the red light waiting to turn right. That cost saving—and given the poor economy of cars then, environmental—measure wasn’t necessarily successful. From the Post:
“Discovery Channel’s MythBusters and the Boston Globe have reported on how companies such as United Parcel Service save money by taking routes that maximize right turns. Although UPS’s experience isn’t, strictly speaking, about making right turns on red, it suggests that the maneuver is more fuel-efficient than idling at a traffic light.”
Right Turns on Red Require a Default Policy to Simplify Driving
Since the 1970s, cities have used RTOR restrictions for lots of non-financial or traffic safety reasons. In DC, we used RTOR restrictions to crack down on prostitution. Making it harder to get somewhere fast has served many public goals. But, creating complex rules that burden drivers with constant second-guessing and confusion probably increases danger and lowers the rate of rule compliance.
In general, users of a system—like drivers within the rules of the road—benefit from universal rules with few, well identified, exceptions. Choosing the default preferred action is a signal of the government’s priority. Banning RTORs signals that DDOT or similar agencies prioritize crosswalk safety more than car throughput. The Post endorses Mayor Bowser and DDOT’s “middle of the road” decision to create lots of special zones and unique rules for each intersection, but user experience designer (an expert on how design affects user behavior and its consequences like safety) Patrick Thornton disagrees:
“Don’t make drivers think. When they get in the habit of making rights on red, they may violate a no right on red out of habit, not because they are looking to break the law. And then they may make that right on red, and hit a baby in a stroller.”
“...the proper decision if you want to sometimes allow it is to have explicit signs saying that you can make a right on red, instead of going the other direction and only having a sign if they are banned.”
Left Turns are Also Dangerous
Finally, a reminder from NYC that left turns can be dangerous also for similar reasons: sharp corners, limited sight lines for all road users, and surplus street space used by drivers to get around traffic.